The current memory detection loop will detect all present memory of
a machine. This is true even if the user specified the "mem=" parameter
on the kernel command line.
This can be a problem since the memory detection may cause a fully
populated host page table for the guest, even for those parts of the
memory that the guest will never use afterwards.
So fix this and only detect memory up to a user supplied "mem=" limit
if specified.
Reported-by: Michael Johanssen <johanssn@de.ibm.com>
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The set-program-parameter (SPP) instruction has been renamed to
load-program-parameter (LPP) (see SA23-2260). Reflect this change
and rename all macro/instruction references.
Also remove the duplicate SPP/LPP entry in the kernel disassembler
instruction list.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix name clash with some common code device drivers and add "tod"
to all tod clock access function names.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make use of the pfmf instruction, if available, to initialize storage keys
of whole 1MB or 2GB frames instead of initializing every single page with
the sske instruction.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
MACHINE_HAS_PFMF and MACHINE_HAS_HPAGE actually have the same semantics:
the cpu has the EDAT1 facility installed in zArch mode. So remove one
of the feature flags in machine_flags and rename the other one to EDAT1.
The two old macros simply get mapped to MACHINE_HAS_EDAT1.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Change return code handling of the stsi() function:
In case function code 0 was specified the return value is the
current configuration level (already shifted). That way all
the code that actually copied the stsi_0() function can go
away.
Otherwise the return value is 0 (success) or negative to
indicate an error (currently only -EOPNOTSUPP).
Also stsi() is no longer an inline function. The function is
not performance critical, but every caller would generate an
exception table entry for this function.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This is the s390 port of 70627654 "x86, extable: Switch to relative
exception table entries".
Reduces the size of our exception tables by 50% on 64 bit builds.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The maximum nesting of the cpu topology is evaluated when /proc/sysinfo
is the first time read. This happens without a lock and a concurrent
reader on a different cpu can see and use an invalid intermediate value.
Besides the fact that this race is quite unlikely the worst thing that
could happen is that /proc/sysinfo would contain bogus information about
the machine's cpu topology.
Nevertheless this should be fixed. So move the detection code to the
early machine detection code and since now the value is early available
use it in the topology code as well.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Allow user-space processes to use transactional execution (TX).
If the TX facility is available user space programs can use
transactions for fine-grained serialization based on the data
objects that are referenced during a transaction. This is
useful for lockless data structures and speculative compiler
optimizations.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
So far, large page support was completely disabled with
CONFIG_DEBUG_PAGEALLOC, although it would be sufficient if only the
large page kernel mapping was disabled. This patch enables large page
support with CONFIG_DEBUG_PAGEALLOC, while it prevents the large kernel
mapping in that case.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Follow x86 and MIPS and sort the main exception table at build time.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.
Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
The early_pgm_check_handler() function is also used after the
init phase in s390_reset_system(). Therefore it must not be in
the init section.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The store clock fast instruction saves a couple of instructions compared
to the store clock instruction. Always use stckf instead of stck if it
is available.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently the following mechanisms are available to move active
Linux on System z instances between machines:
* z/VM 6.2 SSI (Single System Image)
* Suspend/resume
For moving Linux instances in this patch the term LGR (Linux Guest
Relocation) is used. Because such an operation is critical, it
should be detectable from Linux. With this patch for both, a live
system and a kernel dump, the information about LGRs is accessible.
To identify a guest, stsi and stfle data is used. A new function
lgr_info_log() compares the current data (lgr_info_cur) with the
last recorded one (lgr_info_last). In case the two data sets differ,
lgr_info_cur is logged to the "lgr" s390dbf.
The following trigger points call lgr_info_log():
* panic
* die
* kdump
* LGR timer
* PSW restart
* QDIO recovery
* resume
This patch also changes the s390dbf hex_ascii view. Now only printable ASCII
characters are shown.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The current code in setup_boot_command_line() uses a heuristic to
detect an EBCDIC command line. It checks if any of the bytes in
the command line has bit one (0x80) set. In that case it is assumed
that we have an EBCDIC string and the complete command line is
converted.
On s390 there are cases where the boot loader provides a kernel
command line that is NULL terminated, but has random data after
the NULL termination. In that case, setup_boot_command_line()
might misinterpret an ASCII string for an EBCDIC string. A
subsequent string conversion can then damage the ASCII string.
This patch solves the problem by checking for NULL termination.
If no EBCDIC character has been found until the the NULL
termination has been found, we now assume that we have an ASCII
string.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
In ESA mode STCKF is not defined even if the facility bit is enabled.
To prevent an illegal operation we must also check if we run a 64 bit kernel.
To make the check perform well add the STCKF bit to the machine flags.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Split out addressing mode bits from PSW_BASE_BITS, rename PSW_BASE_BITS
to PSW_MASK_BASE, get rid of psw_user32_bits, remove unused function
enabled_wait(), introduce PSW_MASK_USER, and drop PSW_MASK_MERGE macros.
Change psw_kernel_bits / psw_user_bits to contain only the bits that
are always set in the respective mode.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When IPL'ing from a block device and an NSS should be created we must
make sure that the kernel image and the initrd are in different 1MB
segments. Otherwise creating the NSS will fail.
So we make sure the initrd is 4MB behind the end of the kernel image
like we do already when IPL via the VM reader is performed.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use snprintf() here as well so we won't have to deal with this again.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch fixed bugzilla #12965:
https://bugzilla.kernel.org/show_bug.cgi?id=12965
The original code contains some inproper use of sprintf
function where a buffer is used both as input string
as well as output string. It should remember the written
bytes in the previous and use that as the offset for
later writing. Also replace sprintf with snprintf.
Signed-off-by: Chen Liu <chenliu@asset.uwaterloo.ca>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move cpu topology facility detection to early setup code where it
should be.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Store the facility list once at system startup with stfl/stfle and
reuse the result for all facility tests.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Improve performance of the sske operation by using the nonquiescing
variant if the affected page has no mappings established. On machines
with no support for the new sske variant the mask bit will be ignored.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use the SPP instruction to set a tag on entry to / exit of the virtual
machine context. This allows the cpu measurement facility to distinguish
the samples from the host and the different guests.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
The savesys_ipl_nss asm function is put into the .init.text section
however it is missing a ".previous" section which would restore the
previous section.
Luckily all functions in early.c are init functions so it doesn't
matter currently.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move the ebcdic to ascii conversion of the kernel parameter line from
head.S to early.c and convert the assembler code to C.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce the MACHINE_IS_LPAR flag for code that should only be
executed if Linux is running in an LPAR.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
After an IPL from NSS the uptime of the system is incorrect. The reason
is that the startup code in head.S is not executed in case of an IPL
from NSS. Due to that sched_clock_base_cc which is used to initialze
wall_to_monotonic contains the time stamp when the NSS has been created
instead of the time stamp of the system start.
Reinitialize the cputime accounting values in create_kernel_nss after
the SAVESYS CP command that created the NSS segment.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If a named saved system (NSS) cannot be defined or saved, print out an
error message with the return code of the underlying z/VM CP command.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Eleminate the local variable machine_flags and always change machine
flags directly in the lowcore.
This avoids confusion about when and why the two variables have to be
synchronized.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Append scpdata to the kernel boot command line. If scpdata starts
with the equal sign (=), the kernel boot command line is replaced.
(For consistency with zIPL and IPL PARM parameters.)
To use scpdata for the kernel boot command line, scpdata must consist
of ascii characters only. If scpdata contains other characters,
scpdata is not appended to the kernel boot command line.
In addition, re-IPL is extended for setting scpdata for the next
Linux reboot.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently, the machine_flags are stored late in the startup
initialization which results in failing machine type checks
(e.g. for MACHINE_IS_VM).
To allow these checks, store the machine flags in the lowcore
when the machine type has been detected.
Moving the machine_flags to the lowcore has been introduced with
git commit 25097bf153
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Our swsusp_arch_suspend() backend implementation disables prefixing
by setting the contents of the prefix register to 0.
However afterwards common code functions are called which might
access percpu data structures.
Since the lowcore contains e.g. the percpu base pointer this isn't
a good idea. So fix this by copying the hibernating cpu's lowcore to
absolute address zero.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch introduces the hibernation backend support to the
s390 architecture. Now it is possible to suspend a mainframe Linux
guest using the following command:
echo disk > /sys/power/state
Signed-off-by: Hans-Joachim Picht <hans@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a read_persistent_clock function that does not just return 0.
Since timekeeping_init calls the function before time_init has been
called move reset_tod_clock to early.c to make sure that the TOD
clock is running when read_persistent_clock is invoked.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently the storage of the machine flags is a globally exported unsigned
long long variable. By moving the storage location into the lowcore struct we
allow assembler code to check machine_flags directly even without needing a
register. Addtionally the lowcore and therefore the machine flags too will be
in cache most of the time.
Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
strlcpy() does already NUL-terminate the destination string.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently we use the cpuid (via STIDP instruction) to recognize LPAR,
z/VM and KVM.
The architecture states, that bit 0-7 of STIDP returns all zero, and
if STIDP is executed in a virtual machine, the VM operating system
will replace bits 0-7 with FF.
KVM should not use FE to distinguish z/VM from KVM for interested
guests. The proper way to detect the hypervisor is the STSI (Store
System Information) instruction, which return information about the
hypervisors via function code 3, selector1=2, selector2=2.
This patch changes the detection routine of Linux to use STSI instead
of STIDP. This detection is earlier than bootmem, we have to use a
static buffer. Since STSI expects a 4kb block (4kb aligned) this
patch also changes the init.data alignment for s390. As this section
will be freed during boot, this should be no problem.
Patch is tested with LPAR, z/VM, KVM on LPAR, and KVM under z/VM.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Most likely it is broken anyway because of the changes in memory
detection. Since we can't test it and there are probably better ways
that using a P390 card, remove support for it.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move memory detection code to own file and also simplify it.
Also add an interface which can be called at any time to get the
current memory layout. This interface is needed by our kernel
internal system dumper.
Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Cc: Michael Holzheu <holzheu@de.ibm.com>
Cc: Frank Munzert <munzert@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Now it is possible to specify additional kernel parameters on the IPL
command line using the IPL PARM option.
If the Linux system is already running, the new reipl sysfs attribute
'parm' can be used to change kernel parameters for the next reboot.
Examples:
IPL C PARM dasd=1234 root=/dev/dasda1
IPL 1234 PARM savesys=mylnxnss
echo "init=/bin/bash" > /sys/firmware/reipl/ccw/parm
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
In case the initrd is located within the bss section it will be
overwritten when the section is cleared. To prevent this just move
the initrd right behind the bss section if it starts within the
section.
The current code already moves the initrd if the bootmem allocator
bitmap would overwrite it. With this patch we should be safe against
initrd corruptions.
Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This adds hugetlbfs support on System z, using both hardware large page
support if available and software large page emulation on older hardware.
Shared (large) page tables are implemented in software emulation mode,
by using page->index of the first tail page from a compound large page
to store page table information.
Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
From: Heiko Carstens <heiko.carstens@de.ibm.com>
From: Carsten Otte <cotte@de.ibm.com>
This lets us use defines for the magic bits in machine flags instead
of using plain numbers all over the place.
In addition on newer machines features/facilities are indicated by the
result of the stfl instruction. So we use these bits instead of trying
to execute new instructions and check wether we get an exception or
not.
Also the mvpg instruction is always available when in zArch mode,
whereas the idte instruction is only available in zArch mode. This
results in some minor optimizations.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch adds functionality to detect if the kernel runs under the KVM
hypervisor. A macro MACHINE_IS_KVM is exported for device drivers. This
allows drivers to skip device detection if the systems runs non-virtualized.
We also define a preferred console to avoid having the ttyS0, which is a line
mode only console.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Heiko Carstens
Hendrik Brueckner
Gerald Schaefer
Martin Schwidefsky
Michael Holzheu
David Howells
Jan Glauber
Chen Liu
Carsten Otte
Hans-Joachim Picht
Christian Ehrhardt
Christian Borntraeger
Gerald Schaefer